Floating cut-off bar and method of use thereof

ABSTRACT

A floating cut-off bar that follows a preselected path of travel over a mold box during a block production cycle. The floating cut-off bar may be coupled to a feed drawer whereby a mechanism allows the floating cut-off bar to engage the specified contour of a division plate in a mold box assembly and aid in material distribution by screeding excess material and delivering additional material to areas of the mold box as necessary and method of making wall blocks therefrom. The specified contour of the division plate is designed to optimally deliver material to achieve a specified uniform density of the block produced for greater structural integrity, strength and durability of the block.

This application is a divisional of U.S. Ser. No. 13/397,940, filed Feb.16, 2012, which is a continuation of U.S. Ser. No. 12/580,368, filedOct. 16, 2009, now abandoned, which claims the benefit of U.S.Provisional Application No. 61/183,611, filed Jun. 3, 2009, the contentsof each of which are hereby incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates generally to the production of concretewall blocks with equal material distribution throughout the mold cavityof the block to produce structurally durable, strong and sound blocks.More particularly the invention relates to producing wall blocks withthe use of a floating cut-off bar (a screed like element) that isseparated yet coupled to a feed drawer for more equal distribution ofconcrete mix material dispersed to all parts of the mold cavity of theblock being produced and can distribute an excess amount of material toareas of the mold as desired to achieve greater uniform density ofmaterial for the block thus making the blocks stronger and more durable.

BACKGROUND OF THE INVENTION

Numerous methods and materials exist for the construction of retainingwalls and landscaping walls. Such methods include the use of naturalstone, poured in place concrete, masonry, and landscape timbers orrailroad ties. Segmental concrete retaining wall blocks which are drystacked (i.e., built without the use of mortar) have become a widelyaccepted product for the construction of retaining walls. Such productshave gained popularity because they are mass produced, and thusrelatively inexpensive. They are structurally sound, easy and relativelyinexpensive to install, and couple the durability of concrete with theattractiveness of various architectural finishes.

These wall blocks are generally produced in a mold assembly whichusually consists of a mold box consisting of side frame and end framewalls forming an enclosed cavity, which rests on a production pallet orplate. The mold box assembly may contain one or multiple mold cavitieswhich are configured to provide the block with a desired size and shapeand thus may include the use of wall liners, cores and core bars,division plates, etc., as known in the art. A mixture or fill, generallyof concrete material, is then poured or loaded into the mold cavities bya feed drawer that has received said material from a batching hopper.The feed drawer moves the fill over the top of the mold box assembly anddispenses the mixture into the mold cavities. As the fill is dispensed,a vibration system may be employed to shake the mold box assembly, thusproviding compaction of the loose fill material to form a solid moldblock. This vibration system functions to consolidate the concretematerial within the mold cavities to produce a more homogeneous concreteproduct.

After the concrete is dispensed into the mold cavities, the feed drawerretracts rearward from over the top of the mold box assembly. Rigidlycoupled on the front of the feedbox is generally a cut-off bar thatstrikes off and levels the mixture in the mold prior to compaction bythe vibration function and stripper shoe compression head assemblyproducing a generally horizontal level surface. Since the cut-off bar isrigidly coupled to the feed drawer it must follow the generallyhorizontal path of the feed drawer. Blocks formed from the mold cavitieshave varying shapes and angles which may require the mix material to bedistributed in different proportions from one mold cavity to another, sothere is no weakening or compromising of the structural integrity and/orstrength of the block from under-filling or over-filling of certainportions of the mold cavities. Since the cut-off bar follows thehorizontal path of the feed drawer there is not a suitable means fordistributing and leaving additional material in one portion of the moldcavity or less material in another portion of the mold cavity as may benecessary/optimal depending upon the shape and size of the block beingproduced. There is a need in the art for a cut-off bar that is notrigidly attached to the feed drawer and which can remove and/orredistribute varying amounts of material as necessary to all portions ofthe mold box cavity. This is most significant where the mold layoutrequires this varying distribution of material when critical elements,such as the moveable sideliners, are oriented perpendicular to thedirection of travel of the feed drawer. If the mold cavities andmoveable sideliners are aligned in parallel with the path of travel,then the rigid cut-off bar can be shaped to deposit the correctproportion of material over the area of need, but when the cavities areperpendicular to the feed drawer, there is currently no effective meansto accomplish the correct distribution. Currently the methods used inthe manufacturing process to aide in material distribution in the moldis to use an agitator grid (an element that sits over the mold box, butunder the feed drawer, which functions to create general distribution ofthe mix material) or to isolate portions of the mold cavities fromreceiving a percentage of the mix material by use of blank-out platesadded to the agitator grid. The blank-out plates are meant to starvesome areas of the mold from receiving their full allotment of mixmaterial, while allowing the other areas to receive the full amount.This currently is the known method of distributing material in a moldbox.

Generally, after the cut-off bar and feed drawer have returned to theirinitial starting positions, the vibration cycle begins prior to thestripper shoe compression head, being lowered onto the consolidatedmaterial in the mold unit cavities of the mold box assembly. Thestripper shoe assembly has plates or stripper shoes mounted to it havingthe same general plan view shape as the cavities in the mold. The platesmay be set in a horizontal or angled orientation, depending on thedesired shape for the top plane or surface of the block being made. Theplates finalize the compression of the concrete material in the moldprior to pushing or stripping the block unit out of the mold in adownward motion. The stripper shoes are traditionally oriented parallelto the top plane of the mold (generally level or flat), but with someproducts they may be angled, or patterned in order to add a definedshape to the top surface of the block facing the stripper shoe plates.

The mold box assembly may be agitated to assist in compression of themix material. Once the vibration cycle is complete, the productionpallet is automatically lowered vertically away from the bottom of themold frame during the de-molding or stripping cycle, and the newlymolded block/blocks are pushed downward through the mold so that theyremain on the manufacturing pallet in preparation of the next cycle ofthe manufacturing process were the blocks are sent to a kiln for acuring cycle. Accordingly, the desired shaped blocks can be readilyremoved from mold cavities.

In commonly assigned U.S. patent application Ser. No. 12/252,837,entitled “RETAINING WALL BLOCK”, the entirety of which is incorporatedherein by reference, a mold assembly for use in producing retaining wallblocks has a horizontal planar bottom member, a stripper shoecompression head (also referred to herein as a stripper shoe headassembly), a mold box having a plurality of side walls that define aplurality of mold cavities having open mold cavity tops and open moldcavity bottoms, the horizontal planar member enclosing the open moldcavity bottoms of the plurality of mold cavities and the stripper shoehead assembly enclosing the open mold cavity tops of the plurality ofmold cavities during a block forming process. Each of the plurality ofmold cavities can be shaped to form a single retaining wall block. Eachof the plurality of mold cavities can be oriented such that the firstside surface is formed at the bottom of the mold cavity and the secondside surface is formed at the top of the mold cavity. One of the sidewalls of each of the plurality of mold cavities can be moveable from aninward block forming position to a retracted discharge position, themoveable sidewall having a three dimensional surface texture or patternthat imparts to the front face of the retaining wall block the threedimensional surface texture or pattern during the block forming process.The sidewalls of each of the plurality of mold cavities can include aforming channel to shape or form an extending flange or lip elementwhich can be used as a means of connecting courses of the block in aretaining wall assembly, if the blocks are oriented with the flange in adownward position (extending downward past the bottom plane of theretaining wall block). The mold assembly further includes a core formingmember which extends vertically into at least one of the plurality ofmold cavities to provide the retaining wall block formed therein with acore extending from the first side surface to the second side surface,or can be partially formed from the first surface, but not all the wayto the second surface. The core forming member can be configured to forma plurality of cores extending from the first side surface to the secondside surface of the retaining wall block and the core or cores can havea variety of shapes, typically selected from round, oval, rectangularand square.

The stripper shoe head assembly includes a lower surface which enclosesthe open mold cavity tops as the stripping cycle is activated. The lowersurface can be angled at an angle α with respect to horizontal such thatthe second side surface of the retaining wall block formed in each ofthe plurality of mold cavities during the block forming process formsangle α with respect to the front face of the retaining wall block, andwherein angle α is optimal between about 5° to 20°, or between about 7½°to 15°. Further, the sidewalls of each of the plurality of mold cavitiescan be shaped to form a vertically extending ridge that provides theretaining wall block with a flange receiving channel formed into a rearportion of the top surface and an upper portion of the rear face of theretaining wall block.

With current feed drawer and cut-off bar distribution techniques, thefeed drawer generally distributes the same amount of material to theentirety of each mold cavity. The cut-off bar, which is rigidly coupledto the front of the feed drawer flows over the mold cavity in ahorizontal path, with the feed drawer dropping and distributing the mixmaterial as it travels. Once the feed drawer has reached its furthestforward motion point, it retracts along its original path where thecut-off bar now functions to screed or cut-off any excess material thatwas deposited over the open cavities of the mold, producing a generallylevel horizontal surface. Typically the mix material is screeded toallow an extra 0.375″ to 1.0″ of extra material over the block moldcavities. This material is the thickness calculated to compress duringthe vibration and compression cycle, such that the block will be formedin its consolidated state to a pre-determined height in the formingcavity. The stripper shoe head assembly, with angled lower surfaces,descends and encloses the open mold cavities as it finalizes thecompression of the material. As the stripper shoe head assembly withangled surfaces lowers to compress the material in the mold cavities,the density of the material is more compressed where the angled surfaceextends the furthest into the mold cavity and the density of thematerial is less compressed where the stripper shoe extends into themold cavity the least. The result is that the block is stronger anddenser where the material has been compressed more and is weaker andless dense where the material has been compressed less. This produces anuneven range of density along the gradient where the material wascompressed by the stripper shoe head assembly, thus the structuralintegrity and strength of the block may be compromised which couldadditionally compromise the structural integrity and strength of anystructure made from the blocks. In addition, where the block is overcompressed, the material may expand (rebound) when released from themold cavity and the planer surfaces may tear as a function of thisrebound effect. Oppositely, areas in the mold cavity that have notreceived enough material may be less compressed and have unfilled,broken and crumbling surface areas or edge conditions.

Current feed drawer and cut-off bar distribution techniques do not allowfor additional material to be distributed to an area of the mold cavitythat may require additional material during compression. This situationarises, for example, in applications where a three-dimensional textureis being imparted onto a surface of the block in the mold cavity.Additional material to fill all crevices and structures of the texturebeing imprinted may be necessary during compression to ensure that thetexture is compacted properly onto the moveable liner which creates thesurface of the block being produced. The additional material that isneeded where the three-dimensional texture is being imprinted is notneeded for the rest of the area of the mold cavity and a materialdistribution technique that could distribute varying amounts of materialthroughout a mold cavity would save on material costs while ensuringthat the block produced is structurally sound, stronger and moreaesthetically pleasing to the eye upon proper imprinting of the texture.

Accordingly, there is a need in the art to correct deficiencies in thedistribution of material in a mold box cavity and the amounts ofcompression within a mold box cavity and to achieve greater overalluniform density of material of the block thus making the blocks strongerand more durable as well as any structure built from the blocks.

SUMMARY OF THE INVENTION

The invention comprises a cut-off bar that is not rigidly attached tothe feed drawer and that can remove and/or redistribute varying amountsof mix material as necessary to all portions of the mold box cavity formore precise and accurate control to enhance the structural strength andintegrity of the block being produced and thus the structure being builtwith the block.

In one embodiment the invention is a cut-off bar that follows apreselected path of travel over a mold box during a block productioncycle. The selected path of travel results in the distribution ofdesired and varying amounts of mix material in the mold cavity. Thecut-off bar may be moveably attached to a feed drawer. The mold box maybe provided with a member defining the selected path of travel. Themember may comprise angled or contoured division plates. The cut-off barfollows the angle or contour of the division plates to distribute thedesired and varying amounts of mix material in the mold cavity. Thefloating cut-off bar may be biased downwardly. The downward biasingforce may be supplied by one or more springs or other biasing member.

In another embodiment the invention is a block manufacturing assemblyincluding a mold box having a member shaped to define a path of travelof a cut-off bar which moves over the mold box during a block productioncycle to screed and distribute mix material in at least one mold cavity.The invention may include a feed drawer to which the cut-off bar may bemoveably attached. The member which defines the path of travel of thecut-off bar may be a division plate having an angled or contoured topsurface which defines the path of travel. Alternatively, the member maycomprise other parts or elements of the mold box or other parts orelements which functionally cooperate with the mold box to define thepath of travel of the cut-off bar.

In a further embodiment the invention comprises a feed drawer having acut-off bar moveably connected thereto. The invention may include a moldbox and wherein the cut-off bar is configured to move over the mold boxat varying heights during a block production cycle to screed orredistribute mix material in at least one mold cavity at depths whichvary depending on the height of the cut-off bar above the mold box.

In another embodiment the invention is a method of manufacturing a blockwith the floating cut-off bar described herein.

In another embodiment the invention is a method of making a blockcomprising removing or screeding varying amounts of mix material fromthe top of a mold cavity. The method includes leaving increased amountsof mix material at a first portion of the mold cavity where additionalmix material is needed and leaving lesser amounts of mix material at asecond portion of the mold cavity where less mix material is needed. Thefirst and seconds portions may be positioned such that a line whichintersects both portions is parallel to a path of travel of a feeddrawer which fills the mold cavity with the mix material.

In a further embodiment the invention is a mold assembly for producingwall blocks comprising a production pallet, a stripper shoe, a mold boxhaving opposed side walls and opposed end walls which together form aperimeter of the mold box, the mold box having an open top and an openbottom, the production pallet enclosing the open bottom of the mold boxduring a block forming process. The assembly further includes a feeddrawer configured to move during the block forming process from a firstposition vertically offset from the mold box to a second position abovethe mold box and back to the first position and to discharge blockforming material into the mold box during the block forming process. Amaterial distribution element is moveably connected to the feed drawerand configured to remove excess block forming material from the mold boxor redistribute block forming material in the mold box as the feeddrawer moves from the second position to the first position during theblock forming process. Additionally, the system includes a controlmember configured to control a path of travel of the materialdistribution element over the mold box as the feed drawer moves from thesecond position to the first position during the block forming process,a height of the material distribution element above the productionpallet changing as the material distribution element moves along thepath of travel during the block forming process. The materialdistribution element may comprise a cut-off bar and the control membermay comprise at least one division plate dividing the mold box into aplurality of mold cavities. The at least one division plate may includea non-linear top surface which defines the path of travel of thematerial distribution element. The material distribution element may beconnected to be moveable with respect to the feed drawer from a downwardposition to an upward position and may be biased to the downwardposition. The stripper shoe may be provided with a lower surfaceconfigured to compress block forming material in the mold box during theblock forming process, the lower surface being angled from horizontal atan angle α which may be in the range of about 5° to 20°.

In a further embodiment the invention is a method of producing wallblocks in a mold assembly which includes a production pallet, a mold boxhaving an open top and an open bottom, a feed drawer and a strippershoe. The method comprises positioning the production pallet beneath themold box to enclose the bottom of the mold box; moving the feed drawerfrom a first position which is vertically offset from the mold box to asecond position above the mold box; depositing block forming materialfrom the feed drawer into the mold box; moving the feed drawer from thesecond position back to the first position; after the block formingmaterial has been deposited in the mold box redistributing the blockforming material within the mold box such that a height of block formingmaterial above the production pallet in a first portion of the mold boxis greater than a height of block forming material above the productionpallet in a second portion of the mold box, the first and secondportions of the mold box being located such that a line which intersectsboth the first and second portions is parallel with a direction oftravel of the feed drawer as it moves from the second position back tothe first position; lowering the stripper shoe to enclose the open topof the mold box and to compress the block forming material within themold box; and removing the block forming material from the mold box. Thestep of redistributing the block forming material in the mold box may beperformed by moving a material distribution element over the mold boxalong a path of travel from a first end of the mold box to a second endof the mold box, a height of the material distribution element above theproduction pallet over the first portion of the mold box being greaterthan a height of the material distribution element above the productionpallet over the second portion of the mold box. The materialdistribution element may be moveably connected to the feed drawer andwherein the redistributing step is performed when the feed drawer ismoved from the second position back to the first position. The mold boxmay include a control member configured to control the height of thematerial distribution element above the production pallet as thematerial distribution element moves along the path of travel. Thecontrol member may comprises at least one division plate dividing themold box into a plurality of mold cavities, the at least one divisionplate having a non-linear top surface which defines the path of travelof the material distribution element over the mold box.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described with reference to the following drawings. Itshould be noted that for purposes of clarity and to better show featuresof the invention certain parts or portions of structure have beenremoved in various drawing figures.

FIGS. 1A and 1B are top and perspective views, respectively, of a moldbox of the present invention. FIG. 1C is a cross sectional view of themold box of FIGS. 1A and 1B through a mold cavity along line C-C of FIG.1A.

FIG. 2 is a perspective view of a feed drawer assembly and mold box ofthe present invention.

FIGS. 3A and 3B are perspective views of a floating cut-off bar of thepresent invention, shown in connection with the end panel of the feeddrawer.

FIG. 3C is a perspective view of the end panel of the feed drawer of thepresent invention with the floating cut-off bar removed.

FIGS. 4A to 4C are partial front views of different embodiments of thefloating cut-off bar of the present invention.

FIG. 5 is a perspective view of the stripper shoe head assembly of thepresent invention.

FIGS. 6A to 6H are cross-sectional views of a material delivery hopper,feed drawer, floating cut-off bar, mold box, mold cavity, moveable linerplate with 3-dimensional texture, stripper shoe head assembly andmanufacturing pallet demonstrating a variety of typical functionpositions during a mold production cycle of the present invention.

FIGS. 7A and 7B are front views of mold division liners with varyingshapes used to create separate mold cavities, the shapes beingselectable to offer varying amounts of mix material to be deposited onthe top surface of a block being formed in the cavities.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The blocks produced from this invention may be made of a rugged, weatherresistant material, such as concrete. Other suitable materials includeplastic, fiberglass, composite materials, steel, other metals and anyother materials suitable for use in molding wall blocks. The surface ofthe blocks may be smooth or may have a roughened appearance, such asthat of natural stone. The blocks are formed in a mold and varioustextures can be formed on the surface, as is known in the art. It shouldbe appreciated that the invention is equally applicable to blocks of allsizes including those whose faces are either larger or smaller than theones referenced herein.

In accordance with an embodiment of the present invention retaining wallblocks are formed in mold box assemblies as described below. The moldbox assemblies have multiple mold cavities and the blocks are formedwith a first side surface resting on the production pallet and thesecond side surface oriented at the top of the open mold cavity. Thisorientation of the blocks takes up less space on the production palletthan if the blocks were oriented in a mold with their top surface on theproduction pallet. Thus, the number of mold cavities in the mold box canbe increased so that a greater number of blocks can be made in aproduction cycle on a production pallet. It should be noted that thepresent invention is applicable to any mold box and the block or blocksformed therein may have any block shape and may have any surface shapeor contour oriented to the top of the mold cavity.

FIG. 1A is a top view and FIG. 1B is a front perspective view,respectively of a mold box 50. FIG. 1C is a cross sectional view of moldbox 50. Mold box 50 includes ten mold cavities consisting of eightprimary retaining wall block cavities 52 and two corner block cavities72, that are used in combination to form a retaining wall, therebyproducing 10 wall blocks in a production cycle on a production pallet.Blocks of different sizes can be made in mold box 50. By way of example,the blocks formed in mold box 50 may have a height (as manufactured inthe bold box) of 8 or 12 inches depending on the height of the moldcavities above the production pallet, a width (as manufactured in themold box) of 4 inches, and a depth of 7 inches. Mold box 50 isconfigured and sized for use with a typical production pallet, which mayhave a size of 18.5 inches by 26 inches. It should be noted that thesize of the production pallet is not limiting and any varying size andshape of blocks may be produced according to the application as needed.It should also be noted that the present invention is applicable to anysize mold box used to form a single or multiple blocks during aproduction cycle.

Mold box 50 generally includes spill pan side walls 80 and 82 and spillpan end wall 84. Mold box 50 also includes opposing first and secondside frame walls 56 and 58 and opposing first and second end frame walls60 and 62.

Mold cavities 52 (eight cavities in mold box 50 as shown in FIG. 1A) areformed by angled division plates 64 and/or side division plate 65,and/or end liners 66 that form the sides walls of the mold cavity, whichalong with moveable side liners 70 and center division plate 63 thatform the end walls of the mold cavity, define a plurality of moldcavities having open mold cavity tops and open mold cavity bottoms. Thedivision plates and end liners are attached to frame walls 56, 58, 60and 62 of the mold box in a known manner. Though rigidly attached, thedivision plates are installed in such a way as to be replaceable whenthey reach a designated degree of wear. Division plates 64 and 65 are oftwo different shapes. Division plate 65 has substantially parallel topand bottom surfaces, while division plate 64 has an angular sloping topshape. FIG. 1C illustrates an elevation view showing the angled shape ofthe angled division plates 64 as they sit in the mold. The angle andcontour of the division plates form a precise, predetermined andcontrolled material distribution pattern that a floating cut-off barwill follow as a feed drawer moves forward and backward as it travelsits path over the mold box to deliver and screed off the mix material.As the feed drawer returns over the mold to its start position, anyexcess material that exists over the predetermined compaction height(approximate 0.375 of an inch to 1.0 inch) will be screeded off the topand the excess material will be allowed to flow back into the feeddrawer. It should be noted that this shape or pattern is not limitingand any pattern could be given to the division plate or plates for theproduction of different sizes and shapes of blocks and materialdistribution patterns depending upon the application and specific blockrequirements.

Mold cavities 72 (two cavities in mold box 50 as shown in FIG. 1A) areformed from division plate 65 and end liner 66 that form side walls ofthe mold cavity, which, along with moveable impression face liners 70and central division plate 63 that form the end walls of the mold,define a plurality of mold cavities having open mold cavity tops andopen mold cavity bottoms. Division plates 64 and 65 are of two differentshapes. As previously noted division plate 65 has substantially paralleltop and bottom surfaces and is used for producing mold cavity 72 whichproduces the corner blocks of the present invention.

Each of the mold cavities have a vertical flange forming channel 34formed by the division plate in the cavities that produce the side wallsextending from the top of the mold box to the bottom and which form aflange on each block. Blocks may be formed with cores. The cores areproduced by typically hollow forms 87 used to create vertical voids orcavities in the blocks and which are attached to the core bars 86, whichspan the side frame walls and support the core forms in the blocksproduced in the mold cavities. This is done in accordance with knowntechniques. Mold box 50 also includes moveable side liner mechanisms 68which are attached to movable side liners 70. During the blockproduction cycle the movable side liner mechanisms are positioned in afirst inward or block forming position when the mold cavities are filledwith moldable material. The impression face liners 70 may be createdwith any desired three dimensional texture or pattern and impart to thefront face 12 of the retaining wall blocks any desired three dimensionaltexture or pattern when in this first position. When the blocks havebeen formed and are ready to be discharged from the mold cavities,moveable side liner mechanisms 68 are moved to a second retracted ordischarge position. In the retracted position the impression face linersare spaced from the front face of the blocks far enough to allow theblocks to be discharged from the mold cavities without interference fromthe face liners. It should be understood that the mold box is notlimiting and variations and alternate embodiments may be used asdesired. It should be further understood that a plurality, but not all,of the mold cavities may have moveable side liner mechanisms or none ofthe mold cavities may contain the movable side liner mechanisms.

FIG. 2 illustrates a feed drawer assembly 200 with mold box 50 in aresting position under a mix hopper 400 (not shown in FIG. 2, see FIGS.6A to 6H). Feed drawer assembly 200 includes a feed drawer 202 which isopen at the top to receive material from the mix hopper and the bottomto dispense the material received from the mix hopper into the moldcavities as the feed drawer passes over the top of mold box 50. Feeddrawer 202 has a feed drawer drive mechanism, as known in the art, whichis operable for moving the feed drawer 202 from a first retracted orresting position to a second extended position with the open bottom ofthe feed drawer in communication with the open top of the mold box 50and back to the retracted or resting position again.

Feed drawer 202 has end panel 230 which is rigidly connected to feeddrawer 202 by fasteners 232 which may consist of bolts or the like.Brush 240 is also attached to end panel 230 and may be adjusted forheight depending upon the application. Brush 240 cleans off wastematerial lodged or stuck to stripper shoes coupled to a head plateassembly by means of connecting plungers as known in the art. Thecleaning occurs as the brush, as attached to the feed drawer passes backand forth under the stripper shoe head assembly while the material isdistributed to the mold cavities of the mold box assembly. The brushengages the bottom surfaces of the stripper shoes and dislodges andsweeps any waste material that may have been left from previousproduction cycles. End panel 230 also contains bolt mounting points (notshown) which can be used to mount rigid portions of the cut-off bar andbolt mounting slots 260 and 262 as seen in FIG. 3C which can be used tomovably attach the floating portion of the cut-off bar to the end panelof the feed drawer assembly 202 as discussed further below.

FIGS. 3A to 3C illustrate the manner in which the floating cut-off baris moveably attached to end panel 230 of the feed drawer. FIG. 3Aillustrates a front view of a floating cut-off bar 300 of the presentinvention. In this embodiment of the invention the cut-off bar comprisestwo portions, a floating cut-off bar 300 and fixed cut-off bars 301 and302. Floating cut-off bar 300 has core bar slots 304 that allow thefloating cut-off bar to fit over core bars 86 of mold box 50 withadditional space to allow for the up and down movement of the floatingcut-off bar as it travels the entire horizontal path of the feed drawerassembly 200 from the resting or first position to the second extendedposition back to the resting position, and as the floating cut-off barvertically moves over the angular shape of the division plates 64 ofmold box 50. Protective casings 320 and 322 house springs 321 and 323which are shown without the protective covers in FIG. 3B. The protectivecasings 320 and 322 help to protect the springs form the stresses of theproduction cycle and to additionally help keep material out from betweenthe coils of the spring as material is distributed to the mold box.Protective casings 320 and 322 are secured to the floating cut-off barby fasteners 325. It should be noted that the number of springs is notlimiting and any amount may be employed depending upon the application.

Notches 306 house roller bearing 308 which allow the floating cut-offbar to ride over the angular shaped division plates 64. As the rollerbearings 308 travel along the top surfaces of the angular divisionplates, tabs 309 of the floating cut-off bar, adjacent to notches 306housing the roller bearings 308, extend a predetermined distance intomold cavities 52 of mold box 50 and screed excess material back intofeed drawer 202 as the feed drawer travels back to its resting positionfrom its extended position, after completing material distribution tothe mold box cavities. Roller bearings 308 are used to minimize frictionin the free movement of the floating cut-off bar over the angleddivision plates and may also help to screed away waste material left onthe top surface of the angled division plates.

FIGS. 4A to 4C illustrate various roller bearing profiles and subsequenttop surface profiles of angled division plates that may be employed withthe present invention. FIG. 4A illustrates a flat profile roller bearing308 a which rides and follows the contour of a substantially flat topsurface of an angled division plate 64 a. FIG. 4B illustrates a roundprofile roller bearing 308 b which rides and follows the contour of asubstantially rounded top surface of an angled division plate 64 b. Therounded contour of both the roller bearing and top surface of the angleddivision plate helps to limit the ability of fill material to sit on topof the division plate and to screed or shed away excess material left bydistribution of the feed drawer. This will also help to eliminatematerial build-up, which helps to maintain the durability of the rollerbearings. FIG. 4C illustrates a v-shaped profile roller bearing 308 cwhich rides and follows the contour of a substantially v-shaped topsurface of an angled division plate 64 c. The v-shaped profile of boththe roller bearing and top surface of the angled division plate furtherhelps to shed material and prevent build-up to allow for longer lastingdurability and maintainability of the floating cut-off bar and angleddivision plates and thus the production cycle.

Referring again to FIGS. 3A to 3C rigid cut-off bars 301 and 302 arecoupled by mounting bolts 312 to mounting points of end panel 230 offeed drawer 202. Since the rigid cut-off bars 301 and 302 are fixedlycoupled to the feed drawer, they follow the horizontal path of the feeddrawer and no vertical movement occurs. Rigid cut-off bar 301 hasnotches 307 to ride over end liner 66 and division plate 65 and also hasoptional core bar slot 305. As the rigid cut-off bar 301 is retractedwith the feed drawer after material distribution, tabs 309 help screedexcess material in mold cavities 72 back into the feed drawer andnotches 307 help screed additional material off the end liner anddivision plate. Rigid cut-off bar 302 has notch 307 which rides on endliner 66 and helps to screed excess material off the end liner as thecut-off bar is retracted after material distribution of the feed drawer.

Mounting slots 260 and 262 which can be seen in FIG. 3C. FIG. 3C showsthe back surface of end panel 230 of feed drawer 202 with the floatingcut-off bar 300 removed. Mounting slots 260 and 262 each contain onemounting bracket 280 and two mounting bracket stops 270. Mountingbracket stops 270 secured to end panel 230 by fasteners 271 house thesliding mounting bracket 280 in mounting slots 260 and 262 and allowsfor a predetermined vertical range of motion for the mounting bracket280 in mounting slots 260 and 262. Two mounting bolts 310 attach thefloating cut-off bar 300 to the mounting bracket 280 located inside eachmounting slot 260 and 262 of end panel 230. Since the mounting bolts 310coupled to floating cut-off bar 300 are attached to the mounting bracket280 located inside the mounting slots of the end panel, the floatingcut-off bar is given the vertical mobility of the mounting bracket. Thiscoupling allows the floating cut-off bar to have vertical movementthrough-out the path of the feed drawer while additionally allowing thefloating cut-off bar to be coupled to the feed drawer.

Springs 321 and 323 as shown in FIGS. 3B and 3C are attached to thefloating cut-off bar by brackets 327 which may be welded or attached byother means to end panel 230. Tension screws 328 can be turned to adjustthe coil compaction of the springs to help adjust the tension held bythe springs. The tension contained in the coils of the spring as theyare held in a compressed state constantly acts to push the floatingcut-off bar downward. As the feed drawer drive mechanism extends thefeed drawer 202 and floating cut-off bar 300 from the resting positionto an expanded material distributing position springs 321 and 323 of thefloating cut-off bar 300 have a release of tension while traveling alongthe declining slope of the angular division plate 64 and thus causes thefloating cut-off bar 300 to be forcibly pressed in a downward direction.It should be noted that other suitable means other than springs may beemployed such as hydraulic mechanisms and the like which create/exertmovement in multiple/opposing directions and that the present inventionis not limited to the use of springs to create the downward force.

FIGS. 6A to 6H are partial cross-sectional views of the feed drawer,mold box and pallet and illustrate various functional positions of thefeed drawer and cut-off bar during a typical block production cycle.FIG. 6A shows the initial position of the feed drawer and mold beforematerial from the mix hopper 400 has been loaded into the feed drawer.In FIG. 6B the feed drawer has received the material from the mixhopper. During the production cycle roller bearings 308 engage thecontoured pattern of the angled division plate 64 of mold cavities 52and roll the floating cut-off bar along the top surface of the angleddivision plate 64. In FIG. 6C the floating cut-off bar 300 is pushedvertically downward by the springs 321 and 323 along the descendingslope of the division plate as the feed drawer moves over the moldcavities. In FIG. 6D the floating cut-off bar 300 follows the ascendingslope of the division plate 64 along the horizontal path of the feeddrawer. Tension once again is established in springs 321 and 323 as thecompaction of the coils occurs. In FIG. 6E the feed drawer has completedits forward movement over the mold. Once the material has beendistributed by feed drawer 202 the feed drawer drive mechanism retractsthe feed drawer and floating cut-off bar. In FIG. 6F the roller bearings308 again help the floating cut-off bar to roll on and follow thecontoured pattern of the division plate as the feed drawer retracts backtowards its initial or starting position while the floating cut-off bar300 is again pushed vertically downward by the springs 321 and 323 alongthe descending slope of the angular division plate. As the floatingcut-off bar ascends the slope of the division plate 64, tension isre-established in springs 321 and 323 as the compression of the springcoils occurs. In FIG. 6G the feed drawer has been retracted back to itsstarting position.

During retraction of the feed drawer the floating cut-off bar 300 isalso retracted back to its starting position. As the floating cut-offbar retracts it travels the horizontal and vertical path of the angulardivision plates and tabs 309 assist to screed any excess materialdelivered to the mold cavities back into the feed drawer and also assistfor redistribution of material to areas that may not have received asufficient amount of fill when the feed drawer distributed material onits way to its second fully extended position over the mold box. Thecontour of the angled division plate is a precise pattern for thefloating cut-off bar to follow for optimal material distribution of themold cavity for production of the wall block. This optimal materialdistribution allows for more precise and accurate control of thestrength and integrity of the wall block being produced, and thus astructure's structural strength and integrity produced from such ablock.

Rigid cut-off bar 301, because of being fixedly attached to the endpanel of feed drawer 202, does not have the vertical movement of thefloating cut-off bar. As the feed drawer drive mechanism extends thefeed drawer and rigid cut-off bar from the resting position to anexpanded material distributing position the rigid cut-off bar 301follows the substantially horizontal path of the feed drawer oversubstantially horizontal end liner 66 and division plate 65 over moldcavities 72. Once the material has been distributed by feed drawer 202the feed drawer drive mechanism retracts the feed drawer and rigidcut-off bar and tabs 309 assist to screed any excess material deliveredto the mold cavities back into the feed drawer and also assist forredistribution of material to areas that may not have received asufficient amount of fill when the feed drawer distributed material onits way to its second extended position over the mold cavities 72. Thecombination of floating cut-off bar and rigid cut-off bar attached tothe feed drawer allows for the production of two differenttypes/styles/shapes of blocks in a mold box production cycle. It shouldbe noted that the combination and relative sizes of the floating cut-offbar with rigid cut-off bar is not limiting and differing sizes of eachtype of cut-off bar may be employed. It should be further noted that asingle floating cut-off bar could be used along the entire length of theend panel of the feed drawer to encompass all mold cavities in a moldbox.

FIG. 5 is a bottom perspective view of a stripper shoe head assembly 100in accordance with one embodiment of the present invention. Strippershoe head assembly 100 includes a head plate 102 and stripper shoes 106a and 106 b. A plurality of plungers 104 are attached between the headplate 102 and the upper portion of the stripper shoe 106 a/b. Optionalshoe components used for molding embossed or debossed shapes onto thetop of block surface (not shown) may be received within compatibleopenings in the bottom of the stripper shoe 106 a/b depending upon theapplication. The compression head has plates or stripper shoes that havethe same shape as the cavities in the mold, and are used to compact thematerial in the mold cavities to specific densities and to aid indischarging the blocks from the mold cavities when the production cycleis complete. Typically, a lower surface of the compression head whichcontacts the block at the top of the open mold cavity lies in agenerally horizontal plane. In accordance with the present invention thesurface of the stripper shoe which contacts the second side surface ofthe retaining wall block at the top of the open mold cavity may beeither horizontal as stripper shoe 106 b to create a first type blockcorresponding to mold cavities 72 which may be a generally rectangularcorner block; or may be angled as stripper shoe 106 a to create a secondtype block corresponding to mold cavities 52, the angled surfaceimparting to the second side surface the angle α which may be in therange of 5° to 20°, or between about 7½° to 15°, but it should be notedthe angle is not limiting and any angle could be achieved relative tothe desired angle of the surface of the block being produced.

The surfaces of the stripper shoes 106 a/b which contact the moldablematerial at the open top of the mold cavity forming the second sidesurface of the block may be textured or patterned to impart on thesecond side surface any desired three dimensional texture or pattern.Mold box 50 such as shown in FIGS. 1A and 1B having mold cavities whichare configured to form both corner blocks and regular wall blocks withan angled side surface is useful since it requires only one mold box andone mold cycle to produce both types of blocks. It should be understood,however, that mold box 50 may be configured so that corner blocks 72 areformed in one or more mold cavities at any desired location of the moldbox. Further, it is possible to configure the mold box so that all ofthe mold cavities are used to form corner blocks or that all of the moldcavities are used to form regular wall blocks or any desired combinationthereof. The illustration of the corner blocks being formed in the twomold cavities in the upper left of FIG. 1A is merely one example of howthe mold box may be configured.

As previously described, FIGS. 6A to 6H illustrate in cross sectionviews showing the feed drawer 202 and mold box 50, and specificallyillustrating mold cavity 52 with angled division plates 64, of a blockproduction cycle of the present invention. FIG. 6A shows feed drawer 202in a resting or retracted position sitting directly beneath the mixhopper 400 ready to be filled with material and the stripper shoe headassembly 100, located above the mold box is in its initial retractedstarting position. The protective casings 320 and 322 of the springs 321and 323 have been removed from these figures to better illustrate themechanics of the spring and the floating cut-off bar during theproduction cycle.

FIG. 6B shows a pre-determined amount of material, which may be arugged, weather resistant material, such as a low slump concrete mix, asit exits the mix or feed hopper and enters the top opening of the feeddrawer assembly 200. At this time of the production cycle, movableliners 72, if they are employed, are moved into place along with theproduction pallet 74 to close off individual mold cavities 52 (and 72not shown) in preparation for mold cavity fill.

FIGS. 6C to 6E illustrates the feed drawer 202 being driven forward bythe feed drawer mechanism from an initial or resting position to asecond fully extracted position. As the feed drawer proceeds forward thespring of the floating cut-off bar releases tension as the rollerbearings follow the declining angular contour of the angled divisionplate, forcibly pressing the floating cut-off bar downward vertically.As the amount of space between the feed drawer and the angled divisionplate grows along the forward horizontal path of the feed drawer and thedescending slope of division plate 64, more and more tension is releasedfrom the springs to cause the floating cut-off bar to be continuouslypushed down along the angle of the division plate. As the feed drawerprogresses further forward and after it has reached the center divisionplate 63, the floating cut-off bar begins to follow an inclining contourof the angled division liner 64 which causes tension in the springs tobe recaptured as the roller bearings 308 of the floating cut-off barride the top surface of the angled division plate's subsequent incline.The feed drawer, as it moves forward, distributes material through itsbottom opening into mold cavities 52 and brush 240 attached to the endpanel of the feed drawer also cleans off waste debris located on thestripper shoes 106 a (and 106 b not shown) of the stripper shoe headassembly 100 as it passes underneath.

FIGS. 6F to 6G illustrates the feed drawer 202 being retracted by thefeed drawer mechanism as known in the art from a second or extendedposition to an initial or resting position. As the feed drawer retractsback over the mold box the springs of the floating cut-off bar releasetension as the roller bearings follow the declining angular contour ofthe angled division plate forcibly pressing the floating cut-off bardownward vertically. As the amount of space between the feed drawer andthe angled division plate grows along the backward horizontal path ofthe feed drawer, more and more tension is released from the springs tocause the floating cut-off bar to be continuously pushed down along thedeclining slope of the angled division plate 64. As the feed drawerretracts further back and after it has reached center division plate 63,the floating cut-off bar begins to follow an inclining contour of theangled division plate 64 which causes tension in the springs to berecaptured as the roller bearings of the floating cut-off bar ride thetop surface of the angled division plate's subsequent incline. Tabs inthe floating cut-off bar screed excess material in the mold cavitythrough the bottom opening of the feed drawer and relocates excessmaterial to areas of the mold cavity that may be lacking the properspecified amount.

The angle or contour of the division plate is selected to specificallydeposit a greater amount of mix material in areas of the mold whichtypically require more material. For example, it is desirable to depositadditional material in close proximity to movable liner 70 of the moldbox cavity so as to allow for excess material to be compacted into the3-dimensional texture imprint of the movable side liners 70. Thus, theangle or contour of the division plate need not be the actual angle ofthe side of the block being produced. The angled division plate could begiven a stepped contour or any necessary shaped contour as needed by thespecific shape and size of the block being produced in the mold cavity.Two non-limiting examples of such shapes or contours are shown ingreater detail in FIGS. 7A and 7B and discussed further below. Once thefeed drawer has retracted fully back to its resting or initial positionto where it is ready to receive more mix from the mix hopper, and thecut-off bar has fully retracted to where the initial amount of tensionis achieved in springs 321 and 323 a vibration cycle is started to helpconsolidate and compact the concrete mix into all areas and crevasses ofthe mold box cavity.

FIG. 6H illustrates the end of the production cycle after the vibrationcycle has stopped and the movable side liners have retracted and wherebythe stripper shoe compression head assembly has been lowered into moldbox 50 and engaged the material in each mold cavity and compressed it toa specified density. Since the precise amount of excess materialnecessary for proper compression has been uniformly achieved because ofthe accurate distribution of material from the floating cut-off bar'sengagement of the specified contour of the division plate, properstructural integrity and strength of the block in accordance with theproper specified density requirements is achieved.

Excess filling of mix material in a mold cavity may be referred to asover cover. This over cover is exemplified by angle A which is the slopeof the angled division plate and angle B which is the slope of thefinished product and is the same slope as the angular stripper shoes.Angle A of the division plate is larger than that of the finishedproduct's angle B and signifies the amount of compression that appliesto the product as compaction occurs. The stripper shoes 106 a of thestripper shoe head 100 then push the block 10 out of the mold box, atwhich point the production pallet with the final product moves downwardand out from under the mold box. It then proceeds to move laterallyalong a conveyor line to make available the space for the nextproduction pallet to move in under the mold box and up into positioncontacting the bottom of the mold for the next production cycle.

FIGS. 7A and 7B illustrate over cover which is the distribution ofexcess material during a production cycle into each individual moldcavity as necessary for proper block integrity. This over cover allowsfor compaction by vibration and stripper shoe compression to achievegreater uniform density of product necessary for proper block strengthand integrity. The average over cover for a mold cavity is around 8%.FIG. 7A illustrates a single slope angled division plate 64 in moldcavity 52. The single slope provides an example of the over cover abovethe actual unit height that encompasses a range from 8% to 11% ofadditional material over the slope of the angled division liner. The 8%over cover begins at the shallowest part of the mold cavity where thereare relatively few textures and structures that need additionalmaterial. The gradient of the slope increases to 11% where the greatestamount of material is needed to fill in the areas of 3-dimensionaltexture as imprinted in this example by the moveable side liners. Thearea shown in dash indicates the particular block shape of this currentexample. FIG. 7B illustrates a double slope over cover angled divisionplate in a second embodiment of mold cavity 52. The over cover of thisdouble slope has a range of over cover for both slopes. The range ofslope 1 is from 8% to 11% of over cover and the range of slope 2 is from11% to 18% of over cover. The steeper second slope may be applicable incertain applications where even more material is needed for larger3-dimensional texturing from the moveable liners. It should be notedthat a slight incline/decline may be employed between the two slopes forgreater ease and durability of the roller bearing 308 of floatingcut-off bar 300 to ride along during the production cycle. As can beseen from FIGS. 7A and 7B the slope of the side of the block formed inthe mold is less than the slope of the angled division plate forcompression of excess material. The slope of the angled division platesused in an application can have any slope or angle as desired but anaverage range of about 10% to 20% of over cover may be desirable.

Although particular embodiments have been disclosed herein in detail,this has been done for purposes of illustration only, and is notintended to be limiting with respect to the scope of the followingappended claims. In particular, it is contemplated by the inventor thatvarious substitutions, alterations, and modifications may be made to theinvention without departing from the spirit and scope of the inventionas defined by the claims. For instance, the choices of materials orvariations in shapes are believed to be a matter of routine for a personof ordinary skill in the art with knowledge of the embodiments disclosedherein. Further, although the invention has been described in connectionwith blocks having inconsistent heights, densities and surfacedeformities it should be understood that these inventive concepts andembodiments are also applicable to assist in height control, correctdistribution of density and aesthetic improvement to block surfaceconditions caused by any reason.

What is claimed is:
 1. A method of producing wall blocks in a moldassembly which includes a production pallet, a mold box having an opentop and an open bottom, a feed drawer and a stripper shoe, the methodcomprising: positioning the production pallet beneath the mold box toenclose the bottom of the mold box; moving the feed drawer from a firstposition which is vertically offset from the mold box to a secondposition above the mold box; depositing block forming material from thefeed drawer into the mold box; moving the feed drawer from the secondposition back to the first position; after the block forming materialhas been deposited in the mold box redistributing the block formingmaterial within the mold box such that a height of block formingmaterial above the production pallet in a first portion of the mold boxis greater than a height of block forming material above the productionpallet in a second portion of the mold box, the first and secondportions of the mold box being located such that a line which intersectsboth the first and second portions is parallel with a direction oftravel of the feed drawer as it moves from the second position back tothe first position; lowering the stripper shoe to enclose the open topof the mold box and to compress the block forming material within themold box; and removing the block forming material from the mold box. 2.The method of claim 1 wherein the step of redistributing the blockforming material in the mold box is performed by moving a materialdistribution element over the mold box along a path of travel from afirst end of the mold box to a second end of the mold box, a height ofthe material distribution element above the production pallet over thefirst portion of the mold box being greater than a height of thematerial distribution element above the production pallet over thesecond portion of the mold box.
 3. The method of claim 2 wherein thematerial distribution element is moveably connected to the feed drawerand wherein the redistributing step is performed when the feed drawer ismoved from the second position back to the first position.
 4. The methodof claim 3 wherein the mold box includes a control member configured tocontrol the height of the material distribution element above theproduction pallet as the material distribution element moves along thepath of travel.
 5. The method of claim 4 wherein the control membercomprises at least one division plate dividing the mold box into aplurality of mold cavities, the at least one division plate having anon-linear top surface which defines the path of travel of the materialdistribution element over the mold box.
 6. The method of claim 1 whereinthe block forming material is dry cast concrete.